Polyimide type resins attract notice as materials with use of which optical elements such as optical waveguides having good optical characteristics can be produced by a simple production process. Polyimide type resins have a high glass transition temperature (Tg) and a superior heat resistance, and hence optical elements produced are expected to have a long-term reliability, and further, even though they are made of resins, can withstand soldering. In particular, a polyimide type resin containing fluorine has characteristic features such that it has higher light transmission properties and a lower refractive index than polyimide type resins containing no fluorine, and hence it is superior thereto as a material for optical elements.
Such a polyimide type resin containing fluorine, however, has low adherence to glass, quartz, silicon, silicon oxide, silicon nitride, aluminum, aluminum oxide, aluminum nitride, tantalum oxide, gallium arsenide and so forth which are used as materials for substrates of optical elements. Accordingly, an optical-device production method is disclosed in Japanese Patent Application Laid-open No. H7-174930 in which an organozirconium compound layer is formed on a substrate and a polyimide type resin film containing fluorine is formed thereon. Also disclosed in Japanese Patent Application Laid-open No. 2000-241640 is a structure in which a film of an organozirconium compound and a resin film containing no fluorine are superposingly formed and a polyimide type resin film containing fluorine is formed thereon.